4020 lights

[jeffred]

I bought a 4020 last week at an auction. I was able to talk
with the previous owner the day of the sale and he told
me its converted to 12 volt with a three wire alternator.
He said the lights havent worked since the conversion.

Ive been looking at wiring diagrams for a 12 volt
conversion and trying to figure out if something is wrong.
I dont see a blue wire going from the top post of the
starter to the key switch. Is that my light problem? Is
there such a thing as a wiring diagram for a 12 volt
system that utilizes a three wire alternator? What else do
I need to be looking at?

 

[Tx Jim]

If 24 volt wiring harness was converted to 12 volts then there should be a blue & brown wire attached to starter solenoid top post. 24 volt wiring has 2 accessory circuits labeled A & B that split current draw to 12 volts each.

 

[4020man]

Check the light switch and circuit breakers on the panel under the steering wheel. The old 24 volt system was hard on light switches. The blue and brown wires are on the circuit breakers.